Medical grade equipments are usually very expensive, partly because of their complexity, but also because of certifications, legal reasons, and low manufacturing volumes. That’s where open source hardware can make a big difference, and there has been several open source hardware prosthetic hands or arms such as Openbionics hand, but Ebin Philip and his team has tackled another issue with Project OWL, an open indirect ophthalmoscope (OIO) designed for screening retinal diseases, which normally costs between $10,000 to $25,000, but their open source hardware design can be put together for about $400.
The design features a Raspberry Pi 2 board connected to a WaveShare 5″ Touchscreen LCD, a Raspberry Pi Pi IR Camera (M12 lens mount) with 16mm FL M12 lens, a 3 Watt Luxeon LED, two 50x50mm mirrors, a linear polarizer sheet, a 20 Dioptre disposable lens, and various passive components.
While the Raspberry Pi board is not open source hardware itself, Ebin has shared the CAD files for the design, as well as the schematics and gerber files for the RPi shield used in the project on Hackaday.io, where you’ll also find some details about the project log. Assembly instructions are currently missing however. One of the software side, the image are processed through OpenCV to remove background image and reflections.
The main goal of the project is to detect retina problems on diabetic patients in rural areas:
Currently there are over 422 million people worldwide suffering from diabetes. 28.5% of them suffer from Diabetic Retinopathy. 50% of diabetics are unaware about the risk of losing their vision. The number of cases of diabetic retinopathy increased from 4 million in 2000 to 7.69 million in 2010 in US alone. Early detection and Treatment can help prevent loss of vision in most cases.
Detection of Diabetic Retinopathy, requires expensive devices for Retinal Imaging , even the cheapest of them costing more than $9000 each. This makes good quality eyecare, expensive and inaccessible to the less privileged. The key idea in the development of OIO (code-named Project OWL) is to provide an affordable solution to help identify DR and hence prevent cases of “avoidable blindness”.
I’m unclear whether this tool is also appropriate for other tests such as dilated fundus examination, or to check the optical nerves for glaucoma patients, etc…. But if it can be used or adapted for such purposes the implications would even better greater.